Needle guard

ABSTRACT

A needle set includes a needle guard and a winged needle. The needle guard has upper and lower jaws, each of the upper and lower jaws defining a channel and coming together at a hinge. The upper and lower jaws are separated by slots in sides of the needle guard, which slots divide the sides into upper and lower side walls, respectively. The winged needle can be inserted between the upper and lower jaws, with wings of the winged needle passing through the slots. The hinge has an opening and a tube connected to the winged needle passes through the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage filing under 35 U.S.C. § 371of International Application No. PCT/US2016/045885 filed Aug. 5, 2016,which claims priority to U.S. Provisional Application No. 62/202,792filed on Aug. 8, 2015, all of which are hereby incorporated by referencein their entireties.

BACKGROUND

After a needle is used in medical care it is desirable to quickly coverthe needle and render it incapable of subsequent punctures, especiallyfor needles that are used in contact with blood. Utterberg et al. U.S.Pat. Nos. 5,112,311 and 5,562,637 disclose a sliding body or sheathcarried on a tubular set such as a fistula set for hemodialysis, havinga winged needle at the end. The sliding sheath or guard of the citedpatent can be brought forward to enclose the needle as the needle isretracted from the patient, so that the needle is immediately securedagainst accidental needle punctures by the sliding needle guard. Thewings of the needle, which are commonly used in conjunction with avariety of intravenous needles, slide within opposed slots of the needleprotector of the cited patent, and are locked in place when the needleis fully withdrawn into the sliding sheath as described.

FIGS. 1A and 1B show a needle guard 1 according to the prior art. Aneedle guard 1 (also referred to as guard 1) has an upper jaw 4 and alower jaw 6 joined at a hinge 7 formed in a monolithic structuredefining a cavity 12 with slots on either side. The front slots 9 aredefined by bottom edges 8 of the upper jaw side walls 13 and top edges10 of the lower jaw side walls 14. The rear end of guard 1 is defined asthe rounded wedge shape on the left side of FIG. 1A and the front end ofguard 1 is defined as the end of upper jaw 4 shown on the right side ofFIG. 1A. Side walls 13 and 14 have uniform thickness from the front endto the rear end. The front slots 9 define the cavity 12. As may be seenin the drawing, the front slots 9 (one on either side) are tapered suchthat the bottom edges 8 of upper jaw side wall 13 and top edges 10 ofthe lower jaw side wall 14 form an acute angle (indicated by theprojecting lines 18 and 19). Further, the size of the slots is large,larger at the opening of cavity 12 than the thickness of the wings of awinged needle 90 shown in FIGS. 2A-2C, as indicated by the spacingbetween projecting lines 18 and 19. This facilitates easy capture ofneedle wings when the winged needle 90 is drawn into the guard 1, but italso makes it possible for tube 60 and the cannula 52 of the wingedneedle to pass somewhat sideways through the slot as shown in FIG. 2C.In a clinical environment where the process is repeated many times aday, there is a substantial risk of inattention or hasty withdrawalsleading to a partially sideways pull on the needle tubing and consequentmisalignment of the guard.

A rear slot 35 is defined between edges 34 and 36 that also taper asindicated by projections 30 and 32 that are aligned with the edges 34and 36. The rear slot 35 receives wings of a winged needle as discussedbelow. The edges 34 and 36 form an acute angle as indicated by theprojections 30 and 32 of the edges 34 and 36.

A resilient latch 26 is formed to catch the wings of a winged needledrawn into the rear slot 35. The latch 26 has a straight edge facingtoward the upper jaw 4. A finger shield 2 extends forward from the frontend 20 of the upper jaw 4 and curls up as shown in FIGS. 1A and 1B. Thefinger shield 2 has a uniform thickness through its entire length,except for a small drum shaped portion at its front end caused as aremnant of casting or molding. The finger shield 2 facilitates holdingthe guard 1 in position while the needle is drawn into it and furtherprotects the user from the sharp needle point passing below the fingershield 2 when the tube 60 is pulled through needle guard 1. A front end22 of the lower jaw 6 ends behind (i.e., extending less toward the frontthan) a front end 20 of the upper jaw 4 as highlighted by the angleformed between a line 17 that is perpendicular to the guard 1 major axisand a line 16 connecting the front end 22 of the lower jaw 6 that endsbehind a front end 20 of the upper jaw 4.

A winged needle 90 includes a hub 49 which holds cannula 52, asillustrated in FIG. 2A. The hub has wings 53 each of which includes athin wing portion 51 transitioning to thick wing portions 50 which arethicker than thin wing portions 51.

FIGS. 2A-2C illustrate a method of use of a prior art needle guard 1.When the cannula 52 is to be withdrawn from the patient, the guard 1 isheld in place as the tube 60 is pulled back drawing the cannula 52through the cavity 12 and the wings 53 into the slots 9 as shown in FIG.2B. Thin wing portions 51 of wings 53 are supposed engage verticallywith the front slot 9 while thick wing portions 50 are supposed remainhorizontally outside the front slot 9 and provide horizontalstabilization. However, this is not always the case, given the largeopening of the front slot 9.

If the tube 60 is pulled at an angle relative to the prior art needleguard 1, the cannula 52 can protrude through one of the slots 9 as shownin FIG. 2C thereby causing the needle to remain exposed and defeatingthe effect and purpose of the guard 1.

Even when the needle guard of the prior art is used properly, there isalso a risk that a fingertip or other part of a user's or third party'sbody may be inadvertently pushed into or otherwise enter the tipcreating a risk of an accidental puncture. The body part does not needto enter very far because the housed needle tip is not far from thefront of the device.

SUMMARY

A needle guard reduces the risk of misalignment and concomitantprotrusion of a needle due to imprecise use. In comparison to previousconfigurations, the inventive device may have narrowed slots thatreceive the wings of a winged needle. The slots may further be about asnarrow as the wings are thick. The slots may further be narrower thanthe wings are thick. The slots may have parallel edges such that theyhave a uniform width over a substantial length thereof. The slots mayhave parallel edges such that they have a uniform width over a majoritythereof.

In embodiments, the sides and/or rear end are reinforced to prevent therelative lateral movement of upper and lower jaws which may permit theneedle to slip out the side through one of the slots once drawn into theguard. The resistance to this mode of movement may be further increasedby forming the guard of high density polyethylene (HDPE). Inembodiments, the HDPE has a flexural modulus of over 300 Mpa. Inembodiments, the HDPE has a flexural modulus of over 1000 Mpa. Inembodiments, the HDPE has a flexural modulus of at least 1200 Mpa.

In embodiments, the lower jaw extends beyond the upper jaw. This helpsto protect against use with slightly longer needles due to manufacturingvariability and incomplete retraction of the needle within the guard. Italso facilitates holding and stabilizing the guard against the skin ofthe patient when the needle is retracted. The lower jaw may have arounded forward edge or straight. The rounded edge may increase comfortwhile the straight forward edge may improve ease of manipulation.

In embodiments, a home slot that receives the needle wings in a lockedposition thereby retaining the needle within the guard, has asubstantially constant width. In variants, the home slot is tiltedfurther than prior art embodiments to push the needle up against theupper interior wall of the upper jaw.

In embodiments, ribs are molded into on the back end to facilitate use.The back end may be held rather than using an integral finger shield orguard to hold the shield or guard during the drawing of the needle intothe guard.

In embodiments, a resilient latch by virtue of its shape and the use ofHDPE provides a more distinct tactile feedback upon engagement of thewings.

Objects and advantages of embodiments of the disclosed subject matterwill become apparent from the following description when considered inconjunction with the accompanying drawings. The foregoing summary doesnot comprehend all the embodiments or inventive aspects of the disclosedsubject matter and serves merely to assist the reader.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of thedisclosure, and, together with the general description given above andthe detailed description given below, serve to explain the features ofembodiments of the disclosed subject matter. The accompanying drawingshave not necessarily been drawn to scale. Where applicable, somefeatures may not be illustrated to assist in the description ofunderlying features.

FIGS. 1A and 1B show a needle guard according to the prior art.

FIGS. 2A and 2B illustrate a method of using a prior art needle guard.

FIG. 2C illustrates an improper engagement of a needle with a needleguard according to the prior art.

FIGS. 3A and 3B illustrate a needle guard according to embodiments ofthe disclosed subject matter.

FIG. 4A illustrates a view of a winged needle according to embodimentsof the disclosed subject matter.

FIG. 4B illustrates a view of the winged needle of FIG. 4A being drawninto a needle guard according to embodiments of the disclosed subjectmatter.

FIG. 4C shows a front view of the needle guard shown in FIG. 4B.

FIGS. 5A and 5B illustrate features of a needle guard as well a methodof use of a needle guard according to embodiments of the disclosedsubject matter.

FIGS. 5C and 5D illustrate a feature of an extended lower jaw of thedisclosed embodiments by comparing an embodiment 5C of the disclosedsubject matter with a prior art needle guard 5D.

FIGS. 6A and 6B show an abstract illustration of a needle guard whosefeatures are exaggerated to illustrate the engagement between a needleguard and wings of a needle hub according to embodiments of thedisclosed subject matter.

FIGS. 7A and 7B show an abstract illustration of a needle guard whosefeatures are exaggerated to illustrate the shape of the guard and theengagement between the guard and needle according to embodiments of thedisclosed subject matter and wings of a needle hub.

FIG. 7C illustrates a cross-sectional view across plane C-C′ in FIG. 7B.

FIGS. 7D and 7E illustrate aspects of the molding operation for a needleguard according to embodiments of the disclosed subject matter.

FIGS. 8A-8H and 8J illustrate the progression of a needle hub wingthrough a needle guard with a bridge slot according to embodiments ofthe disclosed subject matter.

FIG. 9 illustrates a cut-away view of a needle guard with a resilientplug according an embodiment of the disclosed subject matter.

FIG. 10 illustrates a cut-away view of a needle guard with an absorbentsurface according embodiments of the disclosed subject matter.

FIGS. 11A and 11B illustrate a needle guard according to embodiments ofthe disclosed subject matter with FIG. 11A showing the configurationafter being freed from a mold and FIG. 11B showing the configurationafter being put in an operating state.

FIG. 12 illustrates a finger shield of a needle guard according toembodiments such as disclosed in FIGS. 11A and 11B.

FIGS. 13A, 13B, and 13C illustrate a method of using a finger shield ofa needle guard according to embodiments of the disclosed subject matter.

FIGS. 14A and 14B illustrate a needle guard according to embodiments ofthe disclosed subject matter.

Embodiments will hereinafter be described in detail below with referenceto the accompanying drawings, wherein like reference numerals representlike elements.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments will hereinafter be described in detail below with referenceto the accompanying drawings, wherein like reference numerals representlike elements.

Needle guards and needle sets according to embodiments of the disclosureprevent accidental punctures of users of the needle guard or caretakersof the users. In particular, features are provided to further protectagainst incorrectly sheathed needles, accidental contact with sheathedneedles, and other problems with prior art needle guards.

Referring to FIG. 4A, a winged needle 90 includes a hub 49 which holdscannula 52. The hub 49 has wings 53 each of which includes two thin wingportions 51 extending laterally on substantially opposite sides of thehub 49. The thin wing portions 51 attach the hub 49 to thick wingportions 50, which are thicker than the thin wing portions 51. Inembodiments the thickness difference is a factor of 2 or 3 or a numberapproximately in that range. The thin wing portion 51 may transition tothe thick wing portion 50 progressively forming an inclined ramp 85 asshown in FIG. 7C. Alternatively, the transition may be abrupt forming astep (not shown). In either case, a valley 93 is defined between theside of the hub 49 and the thick wing portion 50. A similar valley maybe formed on the bottom side of the winged needle 90 (not shown). Thevalley 93 may facilitate the retention and proper alignment of the hub49 by providing interfering engagement between the step or ramp and theedges of the side walls 114 of the lower (and/or upper if such a valleyis present) jaw 106 according to the respective embodiment.

The bottom of the hub 49 and may include a nub 54 projecting downward asshown in FIG. 4A. The nub 54 is illustrated with a flat bottom surfaceand has a height measured down and away from the hub 49. Even though nub54 is illustrated with a flat bottom surface, the bottom surface mayhave a more curved shape. The bottom surface shape of the nub 54 can beshaped to fit the space between side walls 114 of the lower jaw 106 ofneedle guard 101 as illustrated in FIGS. 3A-3B and discussed in moredetail infra. Other shapes for a protrusion such as nub 54 may beprovided, its function being to help align the winged needle 90 with aneedle guard such as needle guard 101 discussed presently by providingan interfering engagement of the protrusion with the side wall 114 edgeleading portion 77 on the lower jaw which may be inserted underneath thehub 49 to initially align the hub 49 with the needle guard 101. Thesefeatures are shown in FIG. 4C.

Referring to FIGS. 4B and 4C, FIG. 4B illustrates the needle guard 101in relation to the needle hub 49 at an initial time during a withdrawalprocedure according to embodiments of the disclosed subject matter. Atube 60 passes through a rear opening 207 of the needle guard 101 andexits through the cavity 112 at the front end. This is a configurationof a needle set 89 that includes the winged needle 90 and needle guard101 as part of the needle set 89. The user does not need to establishthis configuration except for initially positioning the needle guard 101with respect to the winged needle 90 by sliding the needle guard 101along the tube 60. The tube 60 is connected to the winged needle 90. Thewinged needle 90 includes hub 49 and cannula 52. The cannula 52 isnormally inserted at an appropriate site such as a patient's bloodvessel, and the wings 53 of the hub 49 are attached to the patient withtape. When the cannula 52 is to be withdrawn from the patient, theneedle guard 101 is manually held in place using the finger shield 102,raised ribs 124 located at the hinge region thereof, or a combination ofthese. The finger shield's 102 position, shape, and size are selected topermit pressure to be applied at the puncture site where the cannula 52enters the patient's skin. When the needle guard 101 is in thisposition, the lower jaw 106 front edge 122 may be placed under the hub49. If a protrusion such as nub 54 is present, it may be guided by theside wall 114 edge leading portion 77 as shown in FIG. 4C. As the tube60 is pulled back, drawing the cannula 52 through the cavity 112 thewings 53 are guided into the slots 109 as shown, for example, in FIGS.4B, 7A, and 7B. Thin wing portions 51 engage vertically with the frontslot 109 while thick wing portions 50 remain horizontally outside thefront slot 109 and provide horizontal stabilization due to interferingengagement with top edge 110 and/or bottom edge 108. In other words, thevalley 93 may trap the bottom edge 108 of the upper side wall 113 and/ortop edge 110 of the lower side wall 114 within it thereby steering thewinged needle 90 straight (aligned with its axis parallel to thelongitudinal axis of the needle guard 101) with respect to the needleguard 101. Again, at the same time, at least initially, the nub 54, inembodiments where present, may also be guided by the side wall 114 edgeleading portion 77. Note that nub 54 is shown in FIG. 4C merely to showits position relative to the needle guard 101 when the lower jaw isinserted under the hub 49 having a nub 54. The drawing is not intendedto show a disembodied nub or suggest that it is part of the lower jaw.

Note that in embodiments, the needle may be horizontally confined by arespective step or ramp in each of the wings as illustrated in FIG. 7C.That is the left inclined ramp 85 may prevent movement in the rightdirection and the right inclined ramp 85′ may prevent movement in theleft direction. Again the ramps may be steps and the limitation ofmovement is due to interfering engagement with the top edges 110.

The needle guard 101, according to embodiments of the disclosed subjectmatter, reduces the chances of cannula misalignment or other contactwith a needle by providing a variety of features discussed herein,including:

-   -   a. narrow slots that positively and interferingly engage the        needle from an initial point of entry to the slots;    -   b. increased lateral rigidity of the needle guard housing to        prevent misalignment or failure of the slot edges to engage the        needle;    -   c. a lower jaw that protrudes beyond the upper jaw to facilitate        the ability to plate the lower jaw beneath the needle hub prior        to drawing the needle;    -   d. an aperture at the front end that faces away from the needle        tip as a result of an upward facing angle between the extended        lower jaw and the upper jaw;        as well as other features.

FIGS. 3A and 3B show a needle guard 101 substantially as described withreference to FIGS. 4A through 4C. The needle guard 101 may preventaccidental punctures even when the user pulls the tubing at an anglerelative to the needle guard 101. The needle guard 101 has slots definedby top 110 and bottom 108 edges that may be substantially parallel orlinearly converging from a position near the back of the needle guard101 to the front of the needle guard 101. FIGS. 4A and 4B show anembodiment in which the top 110 and bottom 108 edges are parallel. FIGS.3A and 3B show an embodiment where these edges are not parallel butdefine a converging slot that defines a gap that is zero at the frontend and the thickness of a wing of the winged needle at the other end.Either type of slot converging or parallel, may be provided in any ofthe embodiments. The upper and lower jaws may be such that the edgesoverlap, touch, converge but rest just short of touching, depending onthe degree of convergence. Some degree of lateral offset of the edges ofthe upper jaw relative to the lower may be permitted to allow overlap,such as by making one of them slightly wider.

The slot may be made to converge by the structure of the guard and theprocess of cooling the part from a mold where the thickening of theneedle guard 101 at the hinge end causes the upper and lower jaws toclose due to slower cooling at the back part of the hinge portion thanthe front part of the hinge portion. This difference in cooling may becaused by the additional reinforcement provided by the thickened region140. The needle guard 101 is also made rigid through thickening ofcertain portions that affect the flexibility of the needle guard 101.The narrower slot and the increased rigidity make it more difficult forthe tubing of the needle assembly to fit between the lower jaw and theupper jaw. Thus the combination of the thicker rear portion of theneedle guard 101 and the parallel or converging slots prevent escape ofthe needle by providing rigidity that keeps edges defining the slotsaligned laterally and causing cooling of the front side of the hingeregion faster than the heaver read side of the hinge region. Further thelimited width of the slot as compared to the prior art prevents theescape of the needle as well. It is more difficult for the needle tobecome wedged into the slot than in the prior art configuration. Tofurther enhance the rigidity, the choice of materials may be suitablylimited. In embodiments the material may be a rigid polymer as indicatedherein. The increased rigidity and narrower slot guides and secures theneedle wings 53 during the entire removal of the needle, from theinitial point of contact between thin wing portion 51 and the jaws untilthe wings 53 are securely locked in the rear slot 135, to avoid thesharp needle tip extending out the slot opening, avoiding an accidentalneedle puncture.

The needle guard 101 has an upper jaw 104 and lower jaw 106 joined athinge 107 and formed in a monolithic structure, defining a cavity 112with slots on either side. The slots include a front slot 109 and rearslot 135 being defined by the bottom edge 108 of the side wall 113 ofthe upper jaw 104 and the top edge 110 of the side wall 114 of the lowerjaw 106. The front slot 109 may be called the receiving slot.

As may be seen in the drawing, the front slots 109 (one on either side)have a constant, or nearly constant width such that the upper jaw sidewall 113 bottom edges 108 and lower jaw side wall 114 top edges 110 areparallel (indicated by the projecting lines 118 and 119). Further, thesize of the slots is narrow as indicated by the spacing betweenprojecting lines 118 and 119. In embodiments, the slot spacing can be asnarrow, or narrower than, the thickness of the thin wing portion 51,which keeps the cannula 52 contained between the slots.

Upper jaw 104 includes as substantially flat roof 115 and two opposedside walls 113 extending down from the roof 115. Though roof 115 isillustrated as flat, it may be curved or have a triangular cross-sectionin different embodiments which may be combined with all of theembodiments discussed below. The curved roof or the triangularcross-section roof may guide the sharp point of the cannula to a pointand resist sideways movement of the cannula point.

Each side wall 113 has a substantially straight upper edge integral withthe roof 115 and extending down from roof 115. The front end of the sidewall 113 is curved from the front end 120 to a straight bottom edge 108.The bottom edge 108 extends to and abuts the bridge slot 138 asillustrated in FIGS. 3A and 8A.

Side wall 113 does not have a uniform thickness. Instead, the side wallhas a one thickness at the front end and includes a thickened region 140at the rear end (toward the rear of the needle guard 101 shown on theleft side of FIG. 3A). The thickened region 140 extends from the upperjaw side wall 113 through the hinge 107 to the lower jaw side wall 114.The thickened region has a thickness that is greater than the thicknessof the side wall 113 and side wall 114 at the front end. The thickenedregion 140 of the needle guard 101 increases the stiffness of the partand minimizes the lateral bending of the upper and lower jaws. Thislateral movement can cause the slot to open, allowing the needle tubingto wedge open the slot and thus creates the aforementioned condition ofthe cannula being exposed. The thickness of the wall may be greater than1 mm. In embodiments, the wall is 1.25 mm in the thickened rear sectionof the guard. In embodiments, the thin and thick sections are 0.8 mm and1.4 mm, respectively.

The roof 115 of the upper jaw extends from the front of the needle guard101 toward the hinge 107, joining the roof of the hinge 107. The hinge107 has two side walls and two rear slots 135 on opposite sides, asshown in FIGS. 3A and 3B. The rear slot 135 is defined between edges 134and 136 that also taper as indicated by projections 130 and 132 that arealigned with the edges 134 and 136. The rear slot 135 receives wings ofa winged needle as discussed below. The edges 134 and 136 form an acuteangle as indicated by the projections 130 and 132 of the edges 134 and136. The rear end of rear slot 135 terminates in a partial circle. Aresilient latch 126 is formed on the lower jaw side wall 114 to catchthe wings of a winged needle drawn into the rear slot 135.

The edges 134 and 136 have a height (measured in the directionsubstantially perpendicular to roof 115) which is substantially equal orgreater than the thickness of the thick wing portion 50. This enablesthe edges 134 and/or 136 to mate with the valley 93 formed above thinwing portion 51. The thick wing portions 50 remain on the outside of theedges 134 and 136 acting as fences to maintain the correct alignment ofthe needle inside the needle guard 101. The rear slot 135 abuts a bridgeslot 138 which in turn abuts the front slot 109, as shown in FIGS. 3A,3B, and 8A.

The bridge slot 138 projects beyond the point where the extension of thebottom edge 108 and the extension of edge 134 would intersect, as shownin FIG. 8A. The bridge slot 138 thus creates an enlarged space, void,recess, or cavity above the resilient latch 126. The bridge slot 138 hasa length d from one end (where it abuts the rear slot 135) to anopposite end (where it abuts the front slot 109) that is at least aslong as the length of the cross-section of thin wing portion 51, asshown in FIG. 8A. The bridge slot 138 creates a recess at a locationbetween the front slot 109 and the rear slot 135 that provides morespace for the thin wing portion 51 to traverse from the front slot 109to the rear slot 135. The process of the thin wing portion 51 traversingthe slots is illustrated in FIG. 8A-8F, showing the thin wing portion 51progressing through positions as it moves from the front slot 109 at thefront of the needle guard 101 to the rear slot 135 at the rear of theneedle guard 101.

The recess created by the bridge slot 138 is an open space or a voidabove the resilient latch 126. This void has a large aspect ratio suchthat the length d is greater than the height of the void measured formthe top of the resilient latch 126 to the roof of the bridge slot 138.In an embodiment of the disclosed subject matter the aspect ratio of therecess or void created by the bridge slot 138 above the resilient latch126 is 2. In an embodiment the aspect ratio is greater than 2. In anembodiment the aspect ratio is greater than or equal to 3. In anembodiment the aspect ratio is greater than or equal to 4.

In an embodiment, the height of the open space created by the bridgeslot 138 measured from the top of the resilient latch 126 (at the baseof barb 127) is greater than the height of the thin wing portion 51, asshown by the free space above and below the thin wing portion 51 in FIG.8A. In an embodiment, the height of the open space above the upper tipof barb 127 is equal to or smaller than the height of the thin wingportion 51, so that the thin wing portion 51 causes the resilient latch126 to deflect downward when the thin wing portion 51 traverses thebridge slot 138 and presses on the barb 127.

The bridge slot 138 has serpentine shape helps to resist the needlewings moving forward out of the rear slot 135 by bypassing the resilientlatch 126. The bridge slot 138 allows the front slot 109 and the rearslot 135 to be narrow, while allowing the thin wing portion 51 tosmoothly make the turn from the front slot 109 to the rear slot 135. Theshape of the recess formed by the bridge slot 138 provides for a smoothand consistent pull of the winged needle 90 through the needle guard101. In an embodiment, the force required to be exerted on the tube 60to pull the winged needle 90 through the needle guard 101 is constantthrough the pull from the point where the thin wing portion 51 firstengages the front slot 109 until the thin wing portion 51 arrives at therear end of the rear slot 135 and its progress is blocked by the roundedend of the rear slot 135. The pulling force is based on the coefficientof friction between the straight bottom edge 108 and the top edge 110pinching the thin wing portion 51 and on the force required to deflectthe resilient latch 126 when the thin wing portion 51 traverses thebridge slot 138. When the thin wing portion 51 first enters the frontslot 109, the pinching force of the straight bottom edge 108 and the topedge 110 is the only force contributing to the pulling force on the tube60. When the thin wing portion 51 reaches the bridge slot 138, as shownin FIG. 8A, the pinching force of the straight bottom edge 108 and thetop edge 110 is exerted on only a small trailing portion of the thinwing portion 51. At that point, the force to depress the resilient latch126 compensates for the decrease of the pinching force exerted by thestraight bottom edge 108 and the top edge 110, providing for asubstantially constant pulling force on the tube 60. Providing asubstantially constant pulling force provides a smooth and easilyrepeatable motion for the user of the needle guard 101. It is safer touse a needle guard 101, or any sharp object for that matter, whenjarring or jerking movements are avoided.

Resilient latch 126 is partially an extension of the top edge 110 of theside wall 114 of the lower jaw 106, as shown in FIG. 8A. The resilientlatch 126 includes a barb 127 at its rear end, as shown in FIG. 8A.Thus, the upper edge of the resilient latch 126 is not straight, but hasa bend or a kink upward to the tip of barb 127. The upper edge of theresilient latch 126 has a hockey stick shape. The hockey stick shapecreates a larger space between the bridge slot 138 and the resilientlatch 126 as compared to an embodiment that lacks the hockey stickshape. Although FIG. 8A illustrates the upward kink of barb 127 ashaving straight sides, the kink can be formed with an upward curvingedge, curving up from an extension of the top edge 110 toward the sharptip or point of the barb 127.

The resilient latch 126 is capable of movement down toward the lower jawin response to force from the direction of the upper jaw, but it springsback. The resilient latch 126 is positioned such that the cross sectionof thin wing portion 51 can pass through the bridge slot 138 while thethin wing portion 51 depresses the resilient latch 126, as shown inFIGS. 8A-8F. In FIGS. 8A-8F, a cross section of thin wing portion 51 isshown in sequence as it presses down on the resilient latch 126 andpasses though bridge slot 138. The bridge slot 138 creates a clearancespace for the thin wing portion 51 above the upper edge of the resilientlatch 126.

In FIG. 8C the resilient latch 126 is pressed down, but is springs backto its original position once the thin wing portion 51 slides beyond theresilient latch 126, as shown in FIG. 8F. The resilient latch 126 isresilient and springy such that it springs back with speed and forceonce the thin wing portion 51 passes beyond it. This springing back islike strumming a guitar string and creates an audible and also palpablesensation (a click) for the user of the needle guard 101. The audibleand palpable feedback confirm to the user that the needle 90 has beencorrectly retracted, improving the safety of the device. If the userdoes not hear and/or feel the expected feedback, the user will checkclosely to ensure that the needle has been retracted and reduce thelikelihood of an accidental puncture.

The audible and palpable feedback is increased by barb 127 which makesthe resilient latch 126 effectively taller, causing the thin wingportion 51 to press the resilient latch 126 down farther than if therewas no barb. The additional depressing of the latch causes the latch tospring back with more force and increases the feedback for easierperception by the user. The barb 127 also provides a taller obstacle forthe thin wing portion 51 once it has passed into the rear slot 135. Anyreverse movement (i.e., from the rear of the needle guard 101 toward itsfront) is blocked by the barb 127. Moreover, the use of barb 127,instead of making the entirety of the resilient latch 126 taller, allowsthe resilient latch 126 to maintain springiness and maintain a smoothand continuous pulling motion for pulling winged needle 90 into theneedle guard 101. If the resilient latch 126 were made taller in itsentirety, it would become more difficult for the thin wing portion 51 todeform the latch 126 as thin wing portion 51 travels through the slot.

Referring now to FIG. 8G, a projection of the rear slot 135 is indicatedby lines 139A and 139B. It will be observed that the tip portion 137spans the entire of this projection indicating that the path for exit ofthe thin wing portion 51 is effectively blocked by it. Since there is nopath guide that can deform the thin wing portion 51 such as a curvedwall that could guide a leading edge of thin wing portion 51 over thelatch 126, the thin wing portion 51 is effectively blocked by the latch126. This contrasts with the prior art rear slot 35 which is onlypartially blocked. Also, the rear slot 135 is approximately the samewidth as the thin wing portion 51. This is compared to the rear slot 35which is substantially larger than the thin wing portion 51. Inaddition, the bridge slot 138 transition to the rear slot 135 has a wallsection 153 that curves down forming an acute angle with the walls ofthe rear slot 135. The thin wing portion 51 is thus guided down towardthe rear slot 135 (See FIG. 8C) in a direction lateral to the walls ofthe rear slot 135 defining a relaxed S-curve or chicane in the pathdefined by the front slot 109, bridge slot 138, and rear slot 135. Thewall section 153 pushes the thin wing portion 51 against the latch 126causing it to retract (FIGS. 8B to 8C).

Referring again to FIG. 8G, it may also be observed that the front slot109, bridge slot 138, and rear slot 135 have respective axes front slotaxis 171, bridge slot axis 172, and rear slot axis 173. The front slotaxis 171 and bridge slot axis 172 are parallel but not collinear. It mayalso be observed that the transition from the bridge slot 138 to therear slot 135 defines an S-shaped path around the latch 126 tip portion137. In terms of paths, the transitions through front slot 109, bridgeslot 138, and rear slot 135 may be described as a jog followed by anS-shaped bend as shown in FIG. 8J.

As shown in FIGS. 3A and 3B, the edges 134 and 136 are of a reducedthickness (measured in the direction perpendicular to the side walls 113and 114) relative to the thickened region 140, which bounds the edges134 and 136. One effect of this difference in thickness is that uponmolding or casting of the needle guard out of a polymer material, thematerial at edges 134 and 136 cools faster than the material in thethickened region which surrounds edges 134 and 136. The material thatcools faster shrinks and creates tension in the surrounding materialwhich, due to cooling more slowly, is still soft and pliable. Thetension in the thinner material pulls on the still-pliable material,causing the hinge to partially close as it cools. The partial closing ofthe hinge pulls the lower jaw against the upper jaw, biasing themagainst each other. Once the thickened portion cools, the materialsolidifies, setting its shape, and the bias of the upper jaw against thelower jaw persists. This process may be characterized as one where thejaws close slightly. This effect may create the converging shape of theslots. Note also that as a result of this jaw-closing, the draft of theinside of the needle guard 101 may be reduced and even be negative. Thatis, the hollow inside of the needle guard is formed in molding by athree-part mold including two molds that converge toward thelongitudinal axis of the molded part (i.e., the needle guard 101) and acore that fits inside and is drawn out of the front. In the embodimentsshown, the core may have a zero or positive draft such that it can bepulled out of the molded part. If the part cools in the mannerdescribed, the internal draft angles will be reduced and may even benegative. As shown in FIG. 3A, this biasing causes the upper jaw and thelower jaw to come in contact at least at the front end of the needleguard 101.

To illustrate the terms and concepts described consider a molded hollowpart 214 as shown in FIG. 7D. The mold 210 may be a two-part mold thatreleases the part 214 (with legs 218A and 218B) in a direction normal toa plane of the page. A core 212 is inserted making the assembly athree-part mold with two actions (the splitting of the mold parts 210and the withdrawal of the core 212. In order for the core to beremovable from the part 214 the core 212 has to be shaped with a neutral(angle p=0) or positive (angle a=a positive number) draft. If the part214 is a needle guard of any of the embodiments, and the core has aneutral or near-zero draft, then the opening may be characterized by anegative draft after cooling it causes the legs 218A and 218B toconverge (angle n) as shown by converging rays 217 in FIG. 7E. Thus, thepart 214 may have an internal draft angle (or shape) that is negative asa result of being cooled in a manner that causes its shape to change inthis way. In embodiments, the needle guard 101 is molded and the moldshape configured such that the part cools after release from the moldsuch that the thicker walled hinge portion is still somewhat plastic asportion of the hinge portion toward the front cools and shrinks. Thepart 214 is a simplified version of the needle guard molded part. Inpart 214 the hinge portion would correspond the portion indicated at 229and the front of the hinge portion would be the portion at 230. If thefront of the hinge portion is thinner or otherwise cools faster afterrelease from the mold (or is cooled differently inside the mold such asby heat transfer mechanism) so that the front part cools and shrinksfirst, then the negative draft (or more negative draft than a positivedraft of the mold core itself) would be obtained. Other ways to make thejaws “close” are also possible such as by mechanically deforming whilethe part is still plastic or placing an external spring or other urgingmechanism on the part after molding.

In other embodiments, it possible to make the separation between theupper jaw and the lower jaws for a needle guard correspond to thethickness of the wings or such portion thereof that fits into the slotsuch that there is a tight but reasonably low friction engagementbetween the needle guard edges and the wings. In such embodiments thejaws might not touch at the front end, but the front slot may taper awayfrom the hinge toward the front end. When the thin wing portion 51 is atleast as thick as the height of the front slot 109 at its front end andalso at least as thick as the maximum height of the front slot 109, theupper jaw 104 and the lower jaw 106 will grip the winged needle 90firmly but without producing significant friction as it is pulledthrough the needle guard 101, avoiding sideways misalignment of thewinged needle 90. The tightness need only be sufficient to ensurepositive interfering engagement and does not need to actually grip thewings if the interfering engagement, such as between the inclined ramp85 (or step—not shown) and the edge 110. Note also that the interferingengagement between the slot edge and wing can be provided between thetop edge and a feature such as a step or inclined ramp on the uppersurface of the wing, between the bottom edge and a feature such as astep or inclined ramp on the lower surface of the wing, or both.

FIGS. 6A and 6B illustrate a simplified representation of a needle guard101 with front slot 209 and rear slot 335. The front slot 209 has anopening that is large enough to accommodate the winged needle 90 withoutit being pried open. However, a step or inclined ramp 85 may engage theedges and guide the winged needle 90 throughout a length of the frontslot 209 and rear slot 335. A progressively narrowing entrance 290 tothe front slot 209 is shown which provides for a smooth capture (FIG.6B) and engagement of the winged needle thin wing portion 51.

FIG. 7A shows a simplified representation of the front slot 109 and therear slot 135 of an embodiment of the disclosed subject matter as asingle slot, with a front end of the upper and lower jaws coming intocontact. While FIG. 7A is not drawn to scale and omits the resilientlatch 126 and bridge slot 138 for clarity, it illustrates the biasing ofthe two jaws against each other. Tube 60 of the winged needle passesfreely through cavity 112. FIG. 7A shows a cross-section of thin wingportion 51 which extends from winged hub 49 to the thick wing portion50. The thin wing portion 51 is shown as a cross-section but itunderstood that the thick wing portion 50 may be present as in the otherembodiments. Note that the wings can be of any configuration dependingthe embodiment, and preferably the wings have an engagement edgesuitable to confine the hub to a central path through the needle guard.

As tube 60 is pulled in the direction from the front end of the needleguard 101 toward the rear end of the needle guard 101, the thin wingportion 51 comes into contact with the lower jaw 106 and with upper jaw104 and pries them apart as shown in FIG. 7B. Because the jaws arebiased against each other, they exert a force from opposed sides on thethin wing portion 51, keeping the winged needle 90 properly aligned withthe front slot 109 for the entire traversal of the winged needle 90through the front slot 109 and the rear slot 135.

FIG. 7C shows a cross-sectional view between points C and C′, lookinginto cavity 112 when the thin wing portion 51 has pried apart the upperjaw 104 and the lower jaw 106. As seen in FIG. 7C, the jaws maintaincontact with the thin wing portion 51. The thick wing portion 50 isthicker than the thin wing portion 51 and thus creates a wall on theoutside of the front slot 109, avoiding sideways translation or rotationof winged needle 90, so the cannula 52 remains safely within cavity 112.

As shown in FIG. 3A, the top outer surface of the hinge 107 includesraised ribs 124 extending generally perpendicularly to the longitudinalaxis of the needle guard 101. The raised ribs 124 provide a secure gripfor a user of the needle guard 101. A user may press on raised ribs 124to hold the needle guard 101 in place while pulling on tube 60 toretract the winged needle 90. Although parallel ribs are illustrated inthe figures, a different pattern that improves the user's comfort andprovides a more secure grip can be used, including cross hatches,stippling, and a roughened surface. The raised ribs 124 address theneeds of different user approaches to holding the needle guard 101 inplace as the needle is drawn back. Some users prefer the safety ofkeeping fingers away from the front of the needle guard 101 and therefor avoid using the finger shield 102. To provide such users with a moresecure grip on the needle guard 101, the raised ribs 124 are providedwhich not only increase grip, but also provide feedback to the user ofthe position of the user's fingers relative to the needle guard 101. Thepositioning of the raised ribs 124 at the back end on a sloping surfacemakes it easier for the user to locate the position by feel. Also, thesecurity provided by pressing on the sloping surface is increasedbecause the surface faces away from the traction forces that need to beapplied to pull the winged needle through the slots and the latch(described below).

As mentioned above, the hinge 107 abuts the lower jaw 106. Lower jaw 106includes two opposed side walls 114 joined to floor 125. As shown inFIGS. 3A and 3B, front end 122 of the lower jaw 106 extends beyond thefront end 120 of the upper jaw 108 as indicated by the angle formedbetween a line 117 that is perpendicular to the needle guard 101 majoraxis and a line 116 connecting the front end 122 of the lower jaw 106 tofront end 120 of the upper jaw 104. The front end 122 may have roundedshape for increased comfort when the lower jaw is pressed against apatient's skin. The front end 122 may also be straight. In embodiments,the front end 122 has a notch in the center of the front end, resultingin a two-pronged fork that can straddle the cannula 52 from two sideswhen the cannula 52 is withdrawn from the patient and help guide thewinged needle 90 into cavity 112. Preferably such a front edge would berounded, for example defining a “B” shaped front end 122A as indicatedat 177. The extended lower jaw has the additional effect of reducing theintensity of the force to the skin at the front end 122 resulting fromleveraged forces applied to the finger shield 102. In the prior artneedle guard 1 and the disclosed embodiments 101, the magnitude ofleverage applied against the skin is greater than unity due to thesignificant overhang of finger shield 102. In the disclosed embodiments,the lower jaw 106 is extended to the point where it underlies regionwhere the finger is placed for removal of the winged needle 90. Comfortmay further be increased by providing that there is a convex bevel 1401at the forward end of the lower jaw as shown in FIG. 14B.

The side wall 114 of the lower jaw 106 may have a non-uniform thicknesswith a thickened region 140 discussed above. The thickened region 140improves resistance to lateral movement of the lower jaw 106 relative tothe upper jaw 104 so that a thinner region forward thereof may permitgreater economy in the use of polymer where the flexion is less of anissue. The shape of the thickened region is indicated at 147, which isnot intended to indicate that it is a separate part but merely anoutline to highlight the boundaries of the portion indicated at 140. Thethickened region 140 is located at the rear end (hinge end) because theweakest point in the lateral movement of the upper and lower jaws is thehinge region. The channel shaped upper and lower jaws form trusses thathave reasonably good resistance to bending even if the walls are thinover at least a portion thereof. The upper jaw has higher dependingwalls and can tolerate a longer thin span indicated at 149. The lowerwall having lower depending walls is reinforced by thickened region 140further toward the front end of the needle guard 101 so that there is ashorter thin region 145. The hinge arc in back experiences a torsionaltwisting moment about a vertical axis 133 which is harder to resist withthe hollow structure especially with the presence of the opening 207(See FIG. 4B). Thus, the hinge portion 143 is reinforced by thickenedwalls.

Referring also to FIGS. 5A and 5B, the extended lower jaw 106 of theneedle guard 101 permits the convenient placement of the front end 122of the lower jaw under the needle hub 49 adjacent a needle puncture site141 of a patient's body 131. This allows the positioning the fingershield 102 above the puncture site 141. This helps to ensure the hub(nub 54 or equivalent, if present) is, prior to drawing, positionedbetween the 122A side wall 114 edge leading portion 77 as indicated at122A as indicated at 177, as shown in FIG. 3B. The extended length ofthe lower jaw 106 facilitates the accurate placement of the fingershield 102 directly over the needle puncture site 141, providing forprecise placement of gauze holding pressure fingers over the needlepuncture site 141 to control bleeding. The front end 122 of the lowerjaw 106 may be positioned immediately adjacent, and optionally beneath,gauze bandage covering the needle puncture site such that side walls 114provide stabilization for the thick wing portion 50 and thin wingportions 51 immediately when the needle is pulled out and pulled throughthe needle guard 101, as shown in FIG. 5B. Further, the extended lengthplaces the needle wings in the precise position for guiding needle wingsinto the slots.

Additionally, the extended lower jaw reduces ease with which a user caninadvertently insert the finger into the cavity 112 within closeproximity of the locked needle tip. Referring to FIGS. 5C and 5D, theneedle guard 101 with an extended lower jaw 106 is shown in FIG. 5C anda needle guard 1 of the prior art with a shorter lower jaw 6 is shown inFIG. 5D. The aperture defined by the relationship between the upper 104and lower 106 jaws of needle guard 101 of the disclosed subject matterfaces upwardly as indicated by the plane 79A which extends into thepage. A soft body part 81 pressed against this aperture, such as the tipof a finger, may extend past the aperture but it extends in a directionaway from the tip of the cannula 52 in its stored position. The aperturedefined by the relationship between the upper 4 and lower 6 jaws ofneedle guard 1 of the prior art faces downwardly as indicated by theplane 79B which also extends into the page. A soft body part 81 pressedagainst this aperture, such as the tip of a finger, may extend past theaperture in a direction toward from the tip of the cannula 52 in itsstored position. This creates a risk of inadvertent needle stick orcontact with the needle or fluids thereon. Thus, by extending the lowerjaw relative to the upper jaw and the degree to which the lower jawextends beyond the upper jaw, the disclosed subject matter defines anaperture that points at least partially away from the position of thetip of a needle in the locked and stored position.

Referring to FIGS. 5A and 5B, the finger shield 102 is extends from thefront end 120 of upper jaw 104. The finger shield 102 may be integrallyformed with the roof 115 of the upper jaw 104 or may be attached to theupper jaw 104 as a separate component. The finger shield 102 facilitatesholding the needle guard 101 in position while the needle is drawn intoit. As shown in FIGS. 5A and 5B, the shield 102 has a thin portion 1022and a thick portion 1021. The thick portion 1021 is thicker than thethin portion 1022, and is thus less flexible. This allows the fingershield 102 to maintain its shape so that it curls around a user'sfingertip even when the user presses down into the curve of the fingershield 102 toward a gauze place above the cannula 52 puncture site. Thishelps to ensure the finger shield 102 continues to hook the finger ofthe user to help resist the traction forces applied to the needle guard191 as the winged needle 90 is drawn into it.

Referring to FIGS. 14A and 14B, the finger shield 102 in an embodimenthas a uniform thickness. In another embodiment, the upper surface offinger shield 102 may have ribs akin to ribs 124 on hinge 107, thoughthese ribs are not illustrated on finger shield 102 and only on hinge107. The embodiment also has a fixed width of front slot 109 but asindicated above the embodiment may be modified to have the narrowingslot as in FIG. 7A. The present figures show specific details such assurfaces and transitions between surfaces that improve the usability ofthe needle guard 101. These details include the smooth flat roof 115,shape and relative size of the opening 207, and relative thickness ofthe thickened region 140. The drawings also show a to-scale embodiment.Note also that details of the drawing indicate aspects that areessential for molding in a three part dual action injection moldingprocess as will be appreciated by those of skill in the art.

Referring to FIG. 11A, in another embodiment, the finger shield 102 hasa uniform thickness but may also be non-uniform as described withreference to FIGS. 5A and 5B. In an embodiment, a needle guard 501 issubstantially as needle guard 101 in all respects except that as amolded piece 501′ as released from the mold, the finger shield 102 and asafety flap 1023 are molded as shown in FIG. 11A. It will be confirmedby inspection that the shape of molded piece 501′ permits the use of twomold halves and a core that can be drawn out of the internal space ofthe molded unit shown. Thus, as shown in FIG. 11A, the finger shield 102is molded in the position shown above the roof 115 with a safety flap1023 extending away from roof 115 in the direction from the rear of themolded piece 501′ toward the front of the molded piece 501′ to permitthe withdrawal of a mold core in a single-shot, three-part moldingoperation. After molding, the finger shield 102 carrying the safety flap1023 may be pivoted about a living hinge 1027B which is illustrated inFIG. 12, to its final position for use shown in FIG. 11B.

FIG. 12 illustrates a cross sectional view of finger shield 102 withsafety flap 1023 integrally connected to roof 115 of the upper jaw 104.As shown in FIG. 12, portions of material adjacent to the finger shield102 are molded so they are thinner to form living hinges to enable thefinger shield 102 to rotate into position and to allow the safety flap1023 to flex passively when the winged needle 90 is pulled past it.Thus, when the needle guard 101 is used, the finger shield 102 isrotated down about the front end 120 of the upper jaw as shown in FIG.11B, which also rotates safety flap 1023 into the opening of cavity 112,as shown in FIG. 11B. The safety flap 1023 may be thin enough to permitthe winged needle 90 to pass by when it is drawn into the needle guard101, and still overly an inserted needle to protect a user inserting afinger or other body part into the cavity 112, thus further reducing thepossibility of an accidental puncture. Alternatively, the flexibilitythat permits the safety flap 1023 to permit the winged needle to passmay be provided (if the safety flap 1023 itself is thick or otherwiseinflexible) or facilitated by means of a further living hinge 1027A. Thesafety flap 1023 may be coated with an absorbent material and/or may bemade hydrophilic through a surface treatment such as electricaldischarge machining. This will help prevent blood that may be in or onthe cannula 52 from leaking out of the front opening of the needle guard101. An absorbent material block can also be attached to the safety flap1023, similar to the block 802 in FIG. 9. When the finger shield 102 isput into use, the block 802 would be on the inner side of the safetyflap 1023 and in position to absorb stray blood from the cannula 52. Itshould be evident that the safety flap 1023 covers the tip of a cannulain the stored position after it is fully retracted and locked so even ifa body part were pushed into the front end of the needle guard 501, thesafety flap 1023 isolates the body part from the tip of the cannula 52.

In yet another embodiment, after use, the finger shield 102 can befolded and locked in engagement with the lower jaw 106 to block cavity112, as shown in FIGS. 13A-13C. FIG. 13A illustrates the needle guard101 after the winged needle 90 has been fully pulled into the needleguard. The pointed end of the needle is pressed against roof 115 of theupper jaw 104. Though the needle is now safely stored, it isadvantageous to further prevent a user, such as a child, from insertinga finger into the cavity 112. To this end, finger shield 102 has anopening that mates with the front end 122 of the lower jaw. FIG. 13Billustrates the finger shield 102 being bent down toward lower jaw 106,and FIG. 13C illustrates the final position where the finger shield 102is mated to the lower jaw 106, closing off the cavity 112.

Another risk from stored cannulae is leaking blood or other bodilyfluids that remain in the cannula after storage in the needle guard. Amechanism to reduce or prevent or loss of such fluid from a storedcannula provides further utility. To this end, the cavity 112 may beprovided with various devices or coatings to absorb or block the flow ofblood. FIG. 9 shows a cut-away view of needle guard 101 with a resilientblock 801 and 802 placed inside the cavity 112. The block 801 may havetwo parts indicated at 801 and 802 and may be of foam or other materialand may be absorbent, hydrophilic, or hydrophobic. The block parts 801and 802 may be connected by a thin tearable sheet (not shown) to permitthem to be stuffed into the front end of the needle guard 101 aftermolding in a single operation. Alternatively, they may be emplaced by afixture that aligns them with respect to each other. They may be held inplace by adhesive or locked by engagement features in the interior ofthe needle guard such as a roughened surface or pins or some othersuitable mechanism. The space between the two block parts 801 and 802allows the winged needle 90 to pass but helps to block blood or otherfluid from escaping. The block parts 801 and 802 may have other suitableshapes that do not interfere with wings 50 when winged needle 90 ispulled through the needle guard. Block parts 801 and 802 may be of foam,gauze, or other material. In further embodiments, only a single blockpart 801 is used. Absorbent material blocks 801 and 802 can be made of amaterial that not only absorbs stray blood, but is firm enough to alsoprevent accidental needle punctures if a user presses a finger firmlyinto the front opening of the cavity 112 of the needle guard after theneedle has been retracted to attempt to force the jaws apart throughbrute force.

FIG. 10 shows a cut-away view of another embodiment of needle guard 101where cavity 112 has an inner surface 901. The inner surface 901 is theinner surface of side walls 113 and 114 and the inner surface of roof115 and floor 125. The inner surface is coated with an absorbent coatingor hydrophilic surface treatment. The inner surface 901 may be texturedto provide a hydrophilic surface that attracts stray blood drops andcauses them to cling to the inner surface of cavity 112 rather thanfalling out. The embodiment of FIG. 9 will be combined with theembodiment of FIG. 10, where an absorbent coating is provided on innersurface 901 and absorbent material blocks 801 and 802 are provided inthe cavity 112.

The needle guard 101 according to embodiments of the disclosed subjectmatter is made of high density polyethylene (HDPE) which has thermalproperties that can bias the upper jaw against the lower jaw asdescribed above. HDPE has a flexural modulus of over 300 Mpa. Inembodiments, the HDPE has a flexural modulus of over 1000 Mpa. Inembodiments, the HDPE has a flexural modulus of at least 1200 Mpa. Thehigh flexural modulus of HDPE increases the needle guard's resistance totwisting. HDPE use also facilitates sterilization because it iscompatible with gamma irradiation sterilization. HDPE also provides alow coefficient of friction between the wings and the needle guard,making it easy to withdraw the needle into the needle guard with asmooth and continuous motion. Other suitable materials includepolypropylene and low density polyethylene.

An exemplary embodiment of the disclosed subject matter includes aneedle set that has a needle guard (101) and a winged needle (90). Theneedle guard (101) has elongate upper and lower jaws (104, 106) eachdefining a channel (109, 135) and joined at a hinge portion (143), eachjaw having depending side walls (113, 114) with elongate edges parallelto a longitudinal axis of each channel, each edge (108, 110) of each jawbeing aligned with and spaced from a respective edge of the other jawdefining elongate slots along the side walls. The winged needle has acannula (52), a hub (49), and a pair of wings (53). A tube (60) isconnected to the cannula (52) by the hub (49). The hinge (107) has anopening (207) into which the tube (60) is received. The side walls (113,114) are spaced apart to permit the hub (49) to be received between thejaws (104, 106) with the wings (50, 51, 53) in the slots (109, 135).Each elongate slot has an open end opposite the hinge portion and theelongate slots progressively narrow to a first spacing that is narrowerthan a thickness of each wing portion (51) at a point thereof that isaligned with a respective pair of the edges, and thereafter expandslinearly to a second spacing that is substantially equal to thethickness of each wing portion (51).

In an embodiment, the side walls (113, 114) are thicker at the hingeportion (143) than at the open end.

In an embodiment, a cross-section of a cylindrical space between thejaws (104, 106) and in a plane perpendicular to the longitudinal axis isconstant along a majority of a length of the needle guard, except for avertical dimension thereof that diminishes progressively from a maximumdimension at the hinge portion (143) to a minimum dimension at the openend (120, 122), the maximum and minimum dimensions differing by thedifference between the first and second spacings.

In an embodiment, a cross-section of a cylindrical space between thejaws (104, 106) and perpendicular to said longitudinal axis is uniformin a horizontal direction and progresses, in the vertical direction,from a maximum dimension at the hinge portion to a minimum dimension atthe open end, the maximum and minimum dimensions differing by thedifference between the first and second spacings. In an embodiment thefirst spacing may be zero.

In an embodiment, the jaws (104, 106) define a space therebetween thathas a negative draft. The negative draft allows a center mold piece tobe removed from the space between the jaws after the needle guard 101 ismanufactured. In an embodiment the magnitude of the negative draft isequal to the difference between the first and second spacings.

In an embodiment the channels defined by the jaws (104, 106) haveC-shaped cross-sections.

In an embodiment of the disclosure, a method of guarding a needleincludes drawing a winged needle (90) into a cylindrical guard (101)having sidewalls (113, 114) with elongate slots (109, 135) therein, thedrawing including forcing a respective wing (50, 51, 53) of said wingedneedle into a respective one of the slots. The drawing progressivelyforces the elongate slots open to a width equal to a thickness of thewings (50, 51, 53) against an urging force generated by a hinge portion(143) of the channel. During the drawing, a non-parallel orientation ofthe axes of the winged needle and the cylindrical guard is prevented byinterferingly engaging the wings (50, 51, 53) with edges of the elongateslots during the drawing.

In an embodiment the forcing includes prying the cylindrical guard apartby urging the wings (50, 51, 53) into progressively narrowing entrancesof the elongate slots (109).

In an embodiment the interferingly engaging includes interferinglyengaging steps in the surface of the wings (50, 51, 53) with the edges(134, 136).

In an embodiment, the method may include positioning a lower portion(106) of the cylindrical guard underneath the winged needle (90) priorto said drawing.

In an embodiment, the preventing may include, prior to the forcing,guiding a central hub (49) of the winged needle (90) between barriers(114) on either side of said lower portion.

In an embodiment, the drawing may include drawing the wings (50, 51, 53)into expanded slot segments (138) of the elongate slots (109, 135) wherethe width of the slots expands and thereafter, proceeding further, bendswhere an edge of each slot defines a deflectable portion (126), thedrawing further causing the wings to be urged against the deflectableportion as both the deflectable portion and the wings deform, theexpanded slot segments being sized such that tail ends of the wings moveacross the expanded slot segments without friction in an initial stageof passing the deflectable portion.

In an embodiment, the drawing may include drawing the wings (50, 51, 53)into expanded slot segments (138) of the elongate slots (109, 135) wherethe width of the slots expands and thereafter, proceeding further, bendswhere an edge of each slot defines a deflectable portion (126), thedeflectable portion having hook shapes (127) over which a leading edgeof the wings rides after it enters the expanded slot segments, drawingfurther causing the wings to be urged against the deflectable portion asboth the deflectable portion and the wings deform in order to follow theelongate slots through the bends.

In an embodiment, a needle set includes a needle guard (101), a wingedneedle (90) with a cannula (52) that has a hub (49) with a pair of wings(50, 51, 53), and a tube (60) connected to the cannula by the hub. Theneedle guard has elongate upper and lower jaws (104, 106) each defininga channel and joined at a hinge portion (143), each jaw having dependingside walls with elongate edges parallel to a longitudinal axis of eachchannel, each edge of each jaw being aligned with and spaced from arespective edge of the other jaw defining elongate slots (109, 135)along the side walls. The hinge has an opening 207 into which the tube(60) is received and the side walls are spaced apart to permit the hub(49) to be received between the jaws (104, 106) with the wings (50, 51,53) in the slots (109, 135). The lower jaw (106) extends beyond theupper jaw (104).

In an embodiment, the lower jaw (106) is C-shaped at its distal enddefining sloping barriers on each side thereof to permit the lower tojaw (106) to be positioned beneath the hub (49) while the cannula (52)is inserted in a patient.

In an embodiment, the hub (49) has a protrusion or a raised nub (54)that fits between the barriers when the lower jaw is positioned beneaththe hub.

In an embodiment, the lower jaw (106) has a rounded front edge.

In an embodiment, the lower jaw has a rounded surface it its front edge(122) having a center of curvature that runs parallel to a front edgethereof.

In an embodiment, a method of guarding a needle includes drawing awinged needle into a cylindrical guard having sidewalls with elongateslots therein, the drawing including guiding a respective wing of thewinged needle into a respective one of the slots. Prior to the drawing,the method includes positioning a lower portion of cylindrical guardbetween a hub of the winged needle and the skin of a patient to at leastpartially support and guide the hub as it is drawn. During said drawing,the method also includes preventing a non-parallel orientation of theaxes of the winged needle and the cylindrical guard by interferinglyengaging the wings or a hub of the winged needle with edges defining theelongate slots during said drawing.

In an embodiment, the drawing includes forcing effective to pry thecylindrical guard apart by urging the wings into progressively narrowingentrances of the elongate slots until the wings hold the slots open andthe wings can slide therethrough.

In an embodiment, the interferingly engaging includes interferinglyengaging steps in the surface of the wings with the edges.

In an embodiment, the preventing includes, prior to said forcing,guiding a central hub of the winged needle between barriers on eitherside of said lower portion.

In an embodiment, the drawing further includes drawing the wings intoexpanded slot segments of said elongate slots where the width of theslots expands and thereafter, proceeding further, bends where an edge ofeach slot defines a deflectable portion, the drawing further causing thewings to be urged against the deflectable portion as both thedeflectable portion and the wings deform, the expanded slot segmentsbeing sized such that tail ends of the wings move across the expandedslot segments without friction in an initial stage of passing thedeflectable portion.

In an embodiment, the drawing further includes drawing the wings intoexpanded slot segments of the elongate slots where the width of theslots expands and thereafter, proceeding further, bends where an edge ofeach slot defines a deflectable portion, the deflectable portion havinghook shapes or barbs over which a leading edge of the wings rides afterit enters said expanded slot segments, drawing further causing the wingsto be urged against the deflectable portion as both the deflectableportion and the wings deform in order to follow the elongate slotsthrough the bends.

In an embodiment, a needle set includes a winged needle (90) and achannel member (104, 106) having a longitudinal axis. The winged needleincludes a hub (49), a cannula (52), and wings (50, 51, 53). The channelfurther has sidewalls (113, 114) with slots opposite each other andparallel to said axis. The slots are open at an open end of the channelmember and closed at a hinge end of the channel member. Each slot has afirst portion (109) beginning at the open end where it has a constantwidth or a width that increases linearly from the open end toward thehinge end. Each slot has a progressively narrowing entry at the open endleading to the first portion (109). Each slot has a transition portion(138) at an end thereof near the hinge end (143) with a width greaterthan a maximum width of the first portion, the transition having alength that is a minor fraction of the first portion. Each slot has anarrow terminal portion that forms an angle with the first portion andtransition portion such that there is a bend in each slot with theterminal portion on one side and the transition and first portions onthe other side. The transition portion (138) having, along one edgethereof, a latch (126) with a concave niche formed by a corner in saidone edge.

Another embodiment includes a needle guard (101) for protecting a userfrom a needle (90) pulled from a front end of the needle guard to a rearend of the needle guard. The needle guard includes an upper jaw (104), ahinge (107), and a lower jaw (106). The upper jaw includes a roof (115),two opposed upper side walls (113) extending down from the roof, whereeach upper side wall includes an upper edge integral with the roof, acurved side edge at the front end, and a substantially straight bottomedge (108) abutting a bridge slot (138) at a rear end of the bottomedge. The upper jaw abuts the hinge (107), which in turn abuts the lowerjaw (106). The hinge includes an upper hinge edge (134) and a lowerhinge edge (136) defining a rear slot (135). The lower jaw abuts thehinge and includes a floor (125), two opposed lower side walls (114)extending up from the floor toward the upper jaw. Each lower side wallincludes a bottom edge integral with the floor, a top edge (110) facingthe bottom edge (108) of the upper side wall and extending toward thefront end to meet the bottom edge of the lower side wall. The top edgeof the lower side wall and the bottom edge of the upper side wall definea front slot (109). A latch (126) extends from the lower side wallopposite the bridge slot, wherein the front slot defines a cavity (112)opening at the front end of the needle guard, the front slot (109)connects to the rear slot (135), and the latch (126) bends down inresponse to a winged needle (90) passing through the front slot (109)and the bridge slot (138). The latch (126) rises to block the wingedneedle (90) from pulling out of the rear slot once the winged needlepasses beyond the latch.

In another exemplary embodiment disclosed above, the upper side wall(113), the lower side wall (114), and the hinge (107) include athickened region (140) that has wall thickness greater than the wallthickness at other regions of the needle guard.

In another exemplary embodiment disclosed above, the thickened region ofthe upper side wall abuts the hinge.

In another exemplary embodiment disclosed above, the thickened region ofthe lower side wall abuts the hinge.

In another exemplary embodiment disclosed above, the thickened region ofthe hinge abuts the upper jaw and the lower jaw.

In another exemplary embodiment disclosed above, the roof is flat or hasa triangular cross-section, like a gable roof of a house.

In another exemplary embodiment disclosed above, the upper edge of theupper side wall is substantially straight.

In another exemplary embodiment disclosed above, the floor issubstantially flat.

In another exemplary embodiment disclosed above, the lower jaw extendsin the front beyond the upper jaw.

In another exemplary embodiment disclosed above, the floor includes afront edge (122) that has a rounded shape.

In another exemplary embodiment disclosed above, a finger shield (102)extends from a front end of the roof of the upper jaw, the finger shieldincluding a curved strip extending up from the front end of the roof.

In another exemplary embodiment disclosed above, the finger shield (102)includes a thin portion (1022) immediately abutting the roof of theupper jaw, and a thick portion (1021) having a thickness greater thanthe thickness of the thin portion abutting the thin portion.

In another exemplary embodiment disclosed above, the width of the fingershield (102) measured perpendicularly to the upper side wall issubstantially same as the width of the roof (115) of the upper jaw.

In another exemplary embodiment disclosed above, the finger shield (102)is configured to fold toward the lower jaw after the winged needle ispulled into the needle guard, to engage the lower jaw to close the frontend of the needle guard.

In another exemplary embodiment disclosed above, finger shield (102)also includes a safety flap (1023) extending from the roof toward thefloor when the finger shield is pressed toward the lower jaw.

In another exemplary embodiment disclosed above, the rear slot (135) ofthe hinge is bounded by a region of material having a first thicknessthat is smaller than the thickness of the thickened region of the hinge.The region of the material having the first thickness cools faster thanthe thickened region of the hinge when the needle guard is molded orcast. The difference in cooling time pulls the upper jaw (104) towardthe lower jaw (106). This may result in a positive draft of the needleguard 101 even when the mold or cast has a negative draft.

In another exemplary embodiment disclosed above, the upper jaw (104) isbiased against the lower jaw (106) by the hinge (107), and the top edge(110) of the lower side wall is in contact with the bottom edge (108) ofthe upper side wall at least at the front end of the needle guard.

In another exemplary embodiment disclosed above, the top edge (110) ofthe lower side wall is parallel to the bottom edge (108) of the upperside wall.

In another exemplary embodiment disclosed above, the front slot (109)tapers from the front end of the needle guard toward the rear end of theneedle guard.

In another exemplary embodiment disclosed above, the latch (126)includes a barb (127) protruding from latch toward the bridge slot. Thebarb (127) forms a kind or a hockey-stick shape on the upper edge of thelatch (126).

In another exemplary embodiment disclosed above, the winged needle (90)strums the latch when the winged needle passes over and clears the barb(127), producing an audible and palpable click.

In another exemplary embodiment disclosed above, a safety needle setincludes a winged needle (90) having a hub (49) with wings (50, 51, 53)extending in opposite directions, a cannula (52) held in the center ofthe hub, and a tube (60) extending from the hub on a side opposite theneedle. The safety needle set also includes a needle guard (101)according to any combination of the exemplary embodiments disclosedabove.

As used herein, the term “cylinder” or “cylindrical” may refer to ahollow structure and is not limited to a structure with a circularcross-section. For example, a hollow elongate prism or one elongatestructure with an elliptical cross-section or piece-wise closedcross-section may be identified by the term “cylinder.” Note that any ofthe embodiments may be modified by providing additional openings, forexample the floor of the needle guards 101 may be opened (U-shaped) topermit a snap-on type of arrangement that allows the user to emplace theneedle guard over a winged needle and tube set.

Features of the disclosed embodiments may be combined, rearranged,omitted, etc., within the scope of the disclosed subject matter toproduce additional embodiments. Furthermore, certain features maysometimes be used to advantage without a corresponding use of otherfeatures. It is, thus, apparent that there is provided, in accordancewith the present disclosure, a needle guard and associated manufactures,components, systems, and methods of use. Many alternatives,modifications, and variations are enabled by the present disclosure.While specific embodiments have been shown and described in detail toillustrate the application of the principles of the disclosure, it willbe understood that the disclosed subject matter may be embodiedotherwise without departing from such principles. Accordingly,Applicants intend to embrace all such alternatives, modifications,equivalents, and variations that are within the spirit and scope of thepresent disclosure.

The invention claimed is:
 1. A needle set, comprising: a needle guardhaving an upper jaw and a lower jaw, the upper jaw and the lower jaweach defining a channel and being joined at a hinge, the upper jawhaving upper side walls parallel to a longitudinal axis of the needleguard, the lower jaw having lower side walls parallel to thelongitudinal axis, edges of the upper jaw being aligned with and spacedfrom respective edges of the lower jaw and defining slots between theupper side walls and the lower side walls, the upper jaw, the upper sidewalls, the lower jaw, and the lower side walls defining a boundary of avolume inside the needle guard, the volume having a rectangularcross-section shape taken perpendicular to the longitudinal axis; awinged needle having a cannula and a hub with a pair of wings; a tubeconnected to the cannula by the hub; the hinge having an opening intowhich the tube is received; the upper side walls and the lower sidewalls being laterally spaced apart to permit the hub to be receivedbetween the upper jaw and the lower jaw with the wings in the slots;each slot of the slots having an open end opposite the hinge, the slotsprogressively narrowing to a first spacing that is narrower than athickness of each wing of the wings at a point on each wing that will bealigned with a respective pair of said edges when the wings areretracted into the needle guard, and thereafter expanding progressivelyto a second spacing that is substantially equal to said thickness ofeach wing, wherein a height of a first cross-section of the volumeinside the needle guard in a plane perpendicular to said longitudinalaxis and taken at a first point, at the open end of each slot, issmaller than a height of a second cross-section of the volume inside theneedle guard in a plane perpendicular to said longitudinal axis andtaken at a second point, adjacent to the hinge of the needle guard, andthe height of the first cross-section at the first point and the heightof the second cross-section at the second point differing by adifference between said first and second spacings.
 2. The set of claim1, wherein the upper side walls and the lower side walls are thicker atsaid hinge than at said open end of each slot.
 3. The set of claim 1,wherein said first spacing is zero.
 4. The set of claim 1, wherein thevolume inside the needle guard has a negative draft.
 5. The set of claim4, wherein a magnitude of the negative draft is equal to the differencebetween said first and second spacings.
 6. The set of claim 1, whereinthe channel defined by each of the upper jaw and the lower jaw has aC-shaped cross-section.
 7. The set of claim 1, wherein the lower jaw hasa floor that is substantially flat.
 8. The set of claim 7, wherein thefloor includes a front edge that has a rounded shape.
 9. A needle guardfor protecting a user from a winged needle pulled from a front end ofthe needle guard to a rear end of the needle guard, the needle guardcomprising: an upper jaw that includes a roof, two opposed upper sidewalls extending down from the roof, each upper side wall of the twoopposed upper side walls including an upper edge depending from theroof, a curved side edge at the front end, and a substantially straightbottom edge abutting a bridge slot at a rear end of the bottom edge, theupper jaw abutting a hinge; the hinge abutting the bridge slots of theupper jaw and a lower jaw, the hinge including an upper hinge edge and alower hinge edge defining a rear slot; and the lower jaw abutting thehinge and including a floor, two opposed lower side walls extending upfrom the floor toward the upper jaw, each respective one lower side wallof the two opposed lower side walls including a bottom edge dependingfrom the floor, a top edge facing the bottom edge of one of the twoopposed upper side walls and extending toward the front end to meet thebottom edge of the respective one lower side wall, said top edge of therespective one lower side wall and said bottom edge of the one of thetwo opposed upper side walls defining a front slot, and a latchextending from the respective one lower side wall opposite the bridgeslot of one of the two opposed upper side walls, the bridge slot being aslot portion that is distinct from the front and rear slots with avertical slot width that is greater than a vertical slot width of thefront slot and greater than a vertical slot width of the rear slot tofacilitate movement of the winged needle from the front slot to the rearslot, wherein the front slot defines a cavity opening at the front endof the needle guard, the front slot connects to the rear slot, the latchbends down in response to the winged needle passing through the frontslot and the bridge slot and rises to block the winged needle frompulling out of the rear slot, and on each respective side of the needleguard, the bridge slot projects beyond a point where an extension of thesubstantially straight bottom edge of a respective upper side wall ofthe two opposed upper side walls would intersect an extension of theupper hinge edge.
 10. The needle guard according to claim 9, whereineach upper side wall of the two opposed upper side walls, each lowerside wall of the two opposed lower side walls, and the hinge include athickened region that has a first wall thickness that is greater than asecond wall thickness at other regions of the needle guard.
 11. Theneedle guard according to claim 10, wherein the rear slot of the hingeis bounded by a region of a material having a third thickness that issmaller than the first wall thickness of the thickened region of thehinge.
 12. The needle guard according to claim 11, wherein the region ofthe material having the third, smaller wall thickness cools faster thanthe thickened region of the hinge when the needle guard is molded orcast.
 13. The needle guard according to claim 9, wherein the roof isflat.
 14. The needle guard according to claim 9, wherein the upper edgeof each upper side wall of the two opposed upper side walls issubstantially straight.
 15. The needle guard according to claim 9,wherein the floor is substantially flat.
 16. The needle guard accordingto claim 9, wherein the lower jaw extends in the front beyond the upperjaw.
 17. The needle guard according to claim 16, wherein the floorincludes a front edge that has a rounded shape.
 18. The needle guardaccording to claim 9, further comprising: a finger shield extending froma front end of the roof of the upper jaw, the finger shield including acurved strip extending up from the front end of the roof, wherein thefinger shield includes a thin portion immediately abutting the roof ofthe upper jaw, and a thick portion, having a thickness greater than athickness of the thin portion, abutting the thin portion.